Study On Methods Based On Enzyme Inhibition Principle Of Determination To Organophosphorus Residue

Organophosphorus pesticides became the most wildly used pesticides since organochlorine pesticides were forbidden, but most organophosphorus pesticides in the use had strong toxicity, while using too much would cause much potential harm, such as environmental pollution, pharmacological contamination and the toxicosis of people and animals, especially the toxicosis in the vegetables caused by organophosphorus pesticides residue was rather severe. One of the most important preventive measures in this case was to rapidly and accurately determine the residues of organophosphorus pesticides in real samples. In recent years, here were some reports about the fast determination to organophosphorus residue which based on enzyme inhibition principle.This article was based on enzyme inhibition principle and used Plant-esterase and Acetylcholinesteras to determine organophosphorus residue. It was devided into five sections below.1. The methods based on enzyme inhibition principle of determination to organophosphorus residue were reviewed. Grounded on which the enzyme was extracted from, the major methods were: Plant-esterase and Acetylcholinesteras. The method using the Plant-esterase could be divided into two below based on the color reaction principle: Fast Blue B Salt and 2, 6-Dichloroindophenol sodium salt hydrate. The main substance of the color reaction in the method of Acetylcholinesteras was DTNB. Acetylcholinesteras were very expensive and needed to be extracted from animals. The procedure was so complex that the method could only be used in the supermarket of big cities, and it couldn't be widely used in the whole country. Plant-esterase was much cheaper and easily extracted from, which made the method be more widely used in the the fast determination to organophosphorus residue.2. The activity of Plant-esterase extracted from the wheat flour and the corn flour were compared using the method of Fast Blue B Salt, and selected out the much more active one to be the enzyme used in the determination to organophosphorus residue and the factors influencing the enzyme activity were studied. The optimized acid condition was pH 7.5 and the temperature was 45 degree. The factors influencing the determination to organophosphorus residue of this method were studied to find a proper reaction system. It was found that, when in the concentration range of 0～2.5 μg/mL, inhibition percentage versus pesticide concentration was linear and the detection limit of dimethoate, DDVP, phoxim were 0.3,0.2,0.1mg/kg if the detection inhibition percentage was 15%. The method could detect that whether the pesticide residues were over the secure limit when it...